A 30-year-old man with ulcerative colitis develops progressive jaundice and pruritis. ERCP shows multifocal biliary strictures and dilations with a 'beads on a string' appearance affecting both intrahepatic and extrahepatic bile ducts. Liver biopsy shows periductal 'onion skin' fibrosis of large bile ducts. AMA is negative; pANCA is positive. The diagnosis is:
- A Primary biliary cholangitis (PBC)
- B IgG4-related sclerosing cholangitis (autoimmune pancreatitis type 1)
- C Primary sclerosing cholangitis (PSC) ✓
- D Choledocholithiasis with secondary sclerosing cholangitis
Explanation
Primary sclerosing cholangitis (PSC) is a progressive fibro-inflammatory disease of the bile ducts, strongly associated with IBD (70–80% of PSC patients have UC). The 'beads on a string' appearance on ERCP reflects multifocal strictures and dilations. Liver biopsy shows periductal concentric 'onion skin' fibrosis. AMA is negative (unlike PBC); pANCA positivity in PSC is a marker of its association with UC. PSC is a risk factor for cholangiocarcinoma. IgG4-related cholangitis shows IgG4+ plasma cell infiltrate and responds to steroids; PBC is AMA positive with florid duct lesions targeting small interlobular ducts.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.